What causes the distortion of image textures
I think Mr Zak is correct,

It looks like the door and window need to be UV unwrapped. By default all tris are mapped to the same part of the immage. That is why it looks distorted.

with the object selected:

-hit tab to enter edit mode, 

-select all vertices of the door or window (but not both)

-hit u twice to unwrap (multiple options are available after the first u)

good luck